(a) Storm sewers shall be designed to flow just full for the five year intensity-duration- frequency storm using the Rational Method. The minimum pavement gutter elevations shall be at or above the hydraulic grade line for a ten year frequency storm.
For the ten year hydraulic gradient checks, minimum starting point elevation, when a proposed storm drainage system outlets into a nearby stream or ditch, shall be based on the twenty-five year high water elevation. If information is unavailable, the high water elevation shall be determined by following sound engineering principles subject to approval by the Director of Public Service.
(b) All structures within a new street right of way shall be designed to adequately handle the storm drainage of the proposed improvement as determined by the Director of Public Service.
(c) All site development involving one acre or more of property, shall be required to include on-site storm water detention/retention per the City’s current Storm Water Management Plan (“SWMP”). The minimum detention volume for the site shall be equivalent to the storage volume produced from a twenty-five year frequency (post-developed) storm inflow with an allowable discharge of a five year frequency (pre-developed) storm outflow. The storm water detention calculations for the site shall be submitted with the site grading plans and shall be subject to approval by the Director of Public Service.
(d) All storm water collection systems shall be designed to include, but not limited to, storm water treatment for the removal of sediment. The type of storm water treatment shall be in accordance to the applicable best management practice(s) (BMPs) as listed in the City’s current SWMP. All construction and maintenance of storm water collection system shall be in accordance to the Ohio Environmental Protection Agency’s Permit No. OHC000002, or more current permit update. All construction details, involving storm water treatment and maintenance, shall be shown on the Erosion Control Plan for the site, which shall be submitted with the site grading plans subject to review and approval from the Director of Public Service. All developers or property owners shall maintain any post-construction structural BMPs according to the maintenance requirements of said BMP. All post-construction structural BMPs will be inventoried and subject to inspection by the Department of Public Service. Failure to properly maintain the BMP will result in penalties according to subsection (f) hereof.
(e) Notification of Violation; Time Limit. Any person found to be violating any provisions of subsection (d) hereof shall be served by the City with a written notice, stating the nature of the violation, sent by first class mail to the person apparently guilty of the violation. This notice shall be deemed sufficient, in the event of violation, if sent to the address of that person as shown on the Lucas County tax records or water account records. The notice shall, in all cases, set forth a time limit during which all noted violations shall cease and be abated, and appropriate corrective action taken, and if the violator shall not thus comply, the provisions of subsection (f) hereof shall then apply.
(f) Violation Beyond Time Limit; Penalty. Any person who continues any violation beyond the time limit provided for in subsection (d) hereof is guilty of a misdemeanor of the second degree and shall be punished as provided in Section 501.99
of the General Offenses Code.
(g) (1) Drainage ditches shall be enclosed to accommodate the estimated ten year storm when the enclosure is equivalent in capacity to forty-eight inches in diameter or less. Such enclosures shall be constructed, installed and paid for by the developer. All other drainage ditches in or abutting the development shall be realigned, widened and/or deepened to accommodate the estimated storm water run-off. All structures shall be enclosed within new street right of way. Such enclosures shall be adequate to handle the storm drainage and shall be constructed, installed and paid for by the developer. Where flood plains are being reduced or eliminated by the site grading of the proposed development, approval shall be obtained from the applicable agency as to the watercourse’s adequacy to handle the additional water due to the altered land use condition.
(2) Storm hydraulic grade lines shall be based on estimated run-off conditions in watershed ten years from the time the improvement is made. (Ord. 6- 2008. Passed 2-20-08.)